Lyme Disease: Wisconsin Data

Lyme disease is very common in Wisconsin. In fact, Wisconsin is one of the states reporting the highest number of cases each year. Other states reporting high numbers of Lyme disease cases include Minnesota and several states in the northeastern United States.

Wisconsin had 6,379 cases of Lyme disease in 2023, the highest on record. On average, about 4000 cases were reported each year during 2018-2022. The number of reported Lyme disease cases has tripled over the past 15 years.

Lyme disease and the tick species that carries it have spread from the northwestern part of the state to nearly all areas of the state over the past 30 years. This spread has caused more and more cases of the disease.

Lyme disease is preventable and treatable. Learn more about Tick Bite Prevention.

Read about Treatment and Signs and Symptoms of Untreated Lyme Disease from the CDC (Centers for Disease Prevention and Control).

The map and graphs on this page show statewide data for Lyme disease. For more detailed county-level data, see the Environmental Public Health Tracking: Lyme Disease.

For national data, visit the CDC webpage on Lyme Disease Data and Surveillance.

Wisconsin map showing Lyme disease by county

Borrelia burgdorferi data

This graph shows the number of reported Lyme disease cases each year in the state.

This graph shows the number of Lyme disease cases per 100,000 Wisconsin residents per year.

Most cases of Lyme disease occur during June and July. However, it’s possible to get Lyme disease whenever ticks are active. Ticks are active when temperatures are above freezing. It’s important to take steps toward Tick Bite Prevention when spending time outdoors.

Chart showing Lyme disease cases by month of illness. Cases are most common during June and July.

Lyme disease is most common in younger and older people. However, people of any age can get Lyme disease.

Average Lyme Disease (B. burgdorferi) Cases by age group

Borrelia mayonii data

The bacterium Borrelia burgdorferi causes most cases of Lyme disease. However, Borrelia mayonii is a rare, newly emerging species. Borrelia mayonii also causes Lyme disease. It was first detected in 2013 in the Midwest, with 10 cases in Wisconsin residents from 2013 to 2023.